ExtJs - Checkbox selection model, disable checkbox per row and lose clearing all the selections

I have a grid with a checkbox selection model.

There are some rows that not be selectable, based on a value in a field. It's work.

My problem is that clearing all the selections by clicking the checkbox in the column header doesn't work. On this link I see that costa was faced the same problem as me: ExtJs - Checkbox selection model, disable checkbox per row.

This listener is worked, but it's break checkbox clearing.

Code:

xtype: 'grid',
border: false,

selModel: {
    selType: 'checkboxmodel',
    listeners: {
        beforeselect: function(grid, record) {
            if (!record.get('supplier')) {
                return false;
            }
        }
    }

colums:[
....
],
....

Does anyone have an idea how to do this?

Thank you.